HELIX SHAPED INSERT FOR FLOW MOIFICATION IN A DUCT OR STENT

摘要

An insert for a duct which is a helical ribbon. The propeller shaped strip may have a flat surface, possess a longitudinally extending fin or rib along one edge or intermediate between the edges or it may have two fins, at least one of which extends along a lengthwise edge. The insert is located in a duct so that its cross section intersects the ducts diameter cross section and may have a pitch in relation to its length such that one end is angularly displaced from the other by one revolution. The insert which may be made of a biodegradable or biocompatible material, may be lodged inside a vein, artery or a graft or in a stent which may be a mesh cylinder. The insert may be used in industrial or engineering pipework. The insert is to cause vortical or helical fluid flow.